Revision History Sheet
Rev. Date Description
0 19-Nov-13 For Review
CONTENTS
PAGE
1. GENERAL
1.1 Intent 4
1.2 Scope 4
1.3 Codes and Standards 4
1.4 Units 4
1.5 Related Engineering Specifications 4
2. DESIGN
2.1 General 5
2.2 Tracer Manifolds and Tracer Manifold Supplied 5
2.3 Tracer 5
2.4 Condensate Pipes 7
2.5 Supports 7
3. MATERIALS
3.1 Pipe, Valves and Fittings 7
3.2 Traps 7
3.3 Fastening Materials 8
3.4 Copper and Stainless Steel Tube 8
Attachment Fig. : Standard steam tracing system 9
1. GENERAL
1.1 Intent
This specification covers general requirements concerning process and utility piping system
which may be included in the plant constructed by Consortium (hereinafter called EPC1) consist
of :
- Toyo-Thai Corporation Public Company Limited (hereinafter called TTCL)
- Toyo-Vietnam Corporation Limited (hereinafter called TVC)
- Chemical Industry Engineering Joint Stock Company (hereinafter called CECO)
- Vietnam Industrial Construction Corporation (hereinafter called VINAINCON)
1.2 Scope
This specification covers all items requiring steam tracing, such as process and utility piping, in-
line instrument and equipment as shown on the Engineering Flow Diagram (hereinafter referred
to as P&ID). However, the steam tracing piping to be supplied with the manufacturer’s
proprietary or standardized equipment are excluded in general.
1.3 Codes and Standards
Design, fabrication, inspection and tests of steam tracing piping materials and its accessories,
unless otherwise specified in this specification, shall be in accordance with the following codes
and standard.
- ASME B31.3 “Process Piping”.
1.4 Units
Unless otherwise specified, metric, kilogram and Celsius units shall be applied to drawings and
technical documents. However, nominal size of piping components shall be in accordance with
inch system (NPS).
1.5 Related Engineering Specifications
The related Engineering Specifications to supplement this specification are follows:
(1) F032-PP-001 “Piping Design”
(2) F032-PP-004 “Piping Materials”
(3) F032-PP-005 “Piping Supports”
(4) F032-PP-003 “Thermal Insulation Works”
2. DESIGN
2.1 General
2.1.1 Steam tracing shall be provided on all lines, equipment, in-line instruments, where,
under expected ambient temperature, freezing, solidification, rise in viscosity or
separation of fluid or condensation of water in corrosive gas etc., would cause trouble in
normal operations and shut-down unless they are externally heated.
2.1.2 All items requiring steam tracing, such as equipments, in-line instruments and piping
shall be as shown on the applicable P&ID with symbol for steam trace.
2.1.3 Insulation thickness shall be in accordance with the “Engineering Specification for
Thermal Insulation Works” based on service operation temperature of the line to be
traced.
2.1.4 Typical steam tracing piping system is as shown in Fig. 1 of Attached Fig..
2.2 Tracer Manifolds and Tracer Manifold Supplies
2.2.1 Tracer manifold shall be provided only where there are a minimum of 2 tracer supplies
grouped within a 3 m radius, and size of tracer manifold supplied shall be followed as
per below table. Tracer supply other than stated above shall be directly branched from
the steam mains.
Steam Supply
Tracer Size Max. Number
Size (NPS)
O.D. of Branches
“inch”
1/2” 10 mm 2
3/4” 10 mm 4
1” 10 mm 8
2.2.2 Block valves for tracer manifold supplies shall generally be installed at vicinity and
horizontal of the branch part of the steam mains.
2.2.3 Tracer manifold supply shall be branched from the top of steam main, and tracer
supplies branched from the top or horizontal of tracer manifold.
2.3 Tracer
2.3.1 Size of tracer shall generally be tube of outside dia. 10 mm and inside dia. 8 mm.
2.3.2 The minimum number of parallel steam tracers for each tracer size shall be followed in
Table as below;
Size of Piping Tracer Size Minimum Number of Tracer
4B and Smaller Ø10 1 (single)
6B to 16B Ø10 2 (double)
18B and Larger Ø10 3 (triple)
2.3.3 The maximum allowable length of tracer (total length from tracer supply line to
condensate trap) are as follow;
Tracer Size Maximum allowable length (m)
Tube Ø10 40
Pipe ½ (NPS) 70
Pipe ¾ (NPS) 100
2.3.4 The pocket height of tracers shall not exceed 2 m.
2.3.5 Tracers need not have drains even if there should be any pocket.
2.3.6 Each tracer line shall generally have its own steam supply valve and condensate trap.
When the tracers have no pocket and possibility of gravity flow of condensate from all
connected tracer condensate lines (including horizontal piping) is assured, not more than
2 tracers may be connected with one trap.
In this case, each tracer shall have equivalent length and the sum of tracer length shall
not exceed the allowable length specified in par. 2.3.3
2.3.7 Sampling connections, drains, vents, and in-line instruments, such as pressure gauge etc.,
attached to piping or equipment shall generally be traced with the tracer for the piping or
equipment.
2.3.8 The safety valves shall be traced as close as possible to valve seat to avoid malfunction.
2.3.9 The tracer insulated with adequate spacer shall be applied for the following items.
(Refer to Fig. 2 Attachment Fig.)
- Items to be protected from excessive heating, e.g. valves with non-metallic seats,
caustic lines, Benfield lines, Amine lines.
2.3.10 All tracers (including tracer supply and return) shall be bent not to be extremely
flattened.
2.3.11 Tracers shall be fixed with steel bands or steel wire at approximately 1 meter intervals;
however such intervals shall be adequately shortened at the bend place where tracers are
not contracted sufficiently with the pipe.
2.3.12 Expansion loops shall be provided at approximately 24 meter intervals loops at pipe
fittings, changes in direction, valves, and flanges shall serve as expansion loops. (Referto
Fig. 3 of attached Fig.)
2.3.13 The standard locations of tracers are shown in Fig. 4 of Attached Fig.
2.3.14 Steam tracer shall generally be arranged as following figure 5.
2.3.15 Each steam tracer run shall be grouped as much as possible, and shall be supported as
following figure 6.
2.3.16 At process header which mixed tracing and no tracing, tracing shall be done up to the
first block valve following figure 7.
2.4 Condensate Pipes
2.4.1 If condensate is recovered, a block valve shall be installed in the outlet line of the
condensate Trap.
2.4.2 Where condensate is recovered, the condensate manifold shall be, in general, provided
only where there are a minimum of 3 condensate lines grouped within a 3 meter radius
and generally be 2 (NPS).
2.4.3 In case of open condensate, the condensate shall be discharged to the sewer where the
condensate discharge does not give hazard for personnel and not make corrosive
environment for pipings and steel structure.
2.5 Supports
All pipes and tubings including tracer supplies and condensate returns shall be adequately
supported in the field.
3. MATERIAL
3.1 Pipes, Valves and Fittings
In general specifications of piping materials for steam tracing shall be the same as those
applicable to the steam mains. However, the tracer (including tracer supply and return) may be
connected with butt-weld and the branch of manifold fabricated with nozzle weld. Copper and
stainless steel tubes shall be used in accordance with the requirements of this specification.
3.2 Traps
Traps shall be used the thermodynamic type with strainer.
3.3 Fastening Materials
Fastening materials for the tracers shall be as follows;
Material Dimension
Galvanized steel wires or S.W.G #18
Galvanized steel bands 0.4mm x 13mm
Remark : Stainless steel wires and bands shall be used for stainless steel piping and equipment.
3.4 Copper and Stainless Steel Tube
3.4.1 Copper tube having inside diameter of 8 mm and outside diameter of 10 mm shall be
used within the maximum service pressure of 10kgf/cm 2 and temperature of 200oC as far
as there is no corrosion of copper. Stainless steel tube of the same size shall be used for
the pressure and temperature exceeding the above.
3.4.2 Copper tube shall be soft anneal seamless tube of the quality specified in JIS H 3300,
“Copper and Copper Alloy-Seamless Pipes and Tubes”, and stainless steel tube shall be
soft anneal seamless tube of equal or higher grade than SUS 304 TP specified in JIS G
3459, “Stainless Steel Pipes.
3.4.3 All tube fittings shall be of bite type.
Attached Fig. Standard Steam Tracing System
Fig. 1 Steam Tracing Piping System
Fig. 2 Tracer Insulated with Spacer
Fig. 3 Tracer Expansion Loop
.
Fig. 4 Standard Location of tracers
